Ballistic missiles and rockets often include a flight vehicle, such as a kill vehicle, having at least one directional control system. In use, a kill vehicle must often be capable of moving towards a target and away from a missile shroud and from propulsion stages separated from the kill vehicle. Typically, the kill vehicle must also be able to quickly change course, correcting for atmospheric or exo-atmospheric conditions or for sudden movements of the target. The course corrections must often be precise to allow for contact of the kill vehicle with its moving target or for detonation relatively close to the moving target. In order to have precise course corrections it is ideal for the center of gravity of the kill vehicle to be precisely controlled. Firing of motors and burning of fuel therein causes the center of gravity to continually change. Such changes in the center of gravity unbalance the kill vehicle, particularly during course corrections, causing error in the course corrections and requiring subsequent course corrections to counter such error.